Bacteria are capable of producing thin, transparent plastic films (polylactic acid (PLA)) and plastics commonly used for medical applications (poly-3-hydroxybutyrate (PHB)). However, unlike some other bioplastics, coaxing bacteria to make PLA or PHB has traditional required feeding them a diet of sugar (glucose). Thus this class of non-fossil fuel based plastics raises similar food crop issues to corn ethanol.

But Victor Irorere, a Masters student in biotechnology at the University of Warwick in the United Kingdom, has offered an alternative, showing that the bacteria can be coaxed to process waste oil (think french fries) instead of the traditional glucose carbon source.

Comments Mr. Irorere, "Our bioplastic-producing bacterium, Ralstonia eutropha H16, grew much better in oil over 48 hours and consequently produced three times more PHB than when it was grown in glucose. Electrospinning experiments, performed in collaboration with researchers from the University of Birmingham, showed that nanofibres of the plastic produced from oils were also less crystalline, which means the plastic is more suited to medical applications."

PLA and PLB are considered promising alternatives to petroleum plastics if costs can be reduced. One advantage -- aside from improved biocompatibility -- is that the bioplastics are biodegradable, reducing landfill waste.

PLA makes thin films that can be used as plastic wrap or in bags (right).
[Image Source: Google Images]

The study's senior author was Iza Radecka, a senior lecturer in microbiology at U of W. She comments, "The use of biodegradable plastics such as PHB is encouraged to help reduce environmental contamination. Unfortunately the cost of glucose as a starting material has seriously hampered the commercialization of bioplastics. Using waste cooking oil is a double benefit for the environment as it enables the production of bioplastics but also reduces environmental contamination caused by disposal of waste oil."

Following a presentation at the Society for General Microbiology's Autumn Conference, the researchers hope to expand their work to commercial-scale tests.